A significant development in magnetic latching and devices is the subject of the PCT International Publication WO92/03631 on the basis of which U.S. Pat. No. 5,362,116 was issued to David Doyle and Neil Dunne. This invention has been assigned to the assignees of the present invention. The Doyle and Dunne invention relates to a vertically operating magnetic latch particularly for a swimming pool gate with a lost motion arrangement so that a latching pin, after manual retraction and after opening the gate, is retained in an elevated retracted position by spring biasing and the actuating mechanism does not apply downward load-imposing forces against the biasing spring.
While this device has been successfully exploited, the present invention has been conceived to offer novel inventive and alternative embodiments for different applications in a different form. Indeed the present invention may be applied to provide magnetic latching as an alternative to conventional striker plates with spring door latches and the invention may lend itself to versions incorporating locks.
Embodiments of the present invention are envisaged as extending both to manually actuatable versions (such as embodiments having rotatable rotary knobs or rotatable handles) but also extends to actuation by other means such as solenoids or electric motors permits actuation from a remote location. Of particular significance in these embodiments is the inherent characteristics of magnetic latching as demonstrated by the Doyle and Dunne prior patent whereby when a gate or door is swung to its closed position, in contrast to conventional gate latches where force is required to displace a spring biased latch pin initially away from a latching position prior to it entering into latching engagement, with Doyle and Dunne there is no such resistance. This is especially valuable in installations having an automatic door closing device.